Voltage converters of the type related to the subject have become known in various embodiments. For example, JP 2000333455 A shows a bidirectional voltage converter for DC voltage. U.S. Pat. No. 5,473,530, in which it is also explained how an AC voltage can be produced at a pulse-width-modulated signal, shows a DC voltage/AC voltage converter, which only works in a unidirectional manner, however. A direct conversion of a mains-frequency alternating input voltage into a likewise mains-frequency alternating output voltage is described in GB 2 301 239 A, whereby a step-down regulator designed as a flow-through converter without galvanic separation is used, which works with high switching frequency.
Usually voltage converters work fully self-sufficiently, e.g., in industrial operations, whereby they can, if necessary, be switched off or on from a central point.